Study On The Fabrication Of High Temperature Gland-lubricating Layer And Its Function Control Mechanism

High temperature gland-lubricating composite is a new type of high temperature self-lubricating material, which is designed based on the human’s gland sweating mechanism. The anti-wear and high strength metal ceramic substrate with interpenetrating micro-pores is firstly manufactured, and then the lubricants are infiltrated into the micro-pores to form a certain thickness of lubricating layer. In the friction process, the lubricants are driven out from the pores in lubricating layer under the coupling effects of temperature and friction thermal stress, and enrich on the friction surface and thus the lubrication film is developed. Obviously, the lubricating performance of the composite depends on its lubricating layer components design, preparation process and microstructure characteristics. Therefore, the research on the melt-infiltration preparation technology of lubricating layer, lubrication mechanism and lubrication control technology were conducted, which were supported financially by the national natural science foundation (50275110). The research contents are as follows:The component design of lubricants alloy was carried out based on the wettability and solubility of solid lubricants and substrate material. The wetting and lubricating properties of lubricants alloy were studied by wettability test and tribological experiments. The optimal component design of lubricants alloy was realized and the technology of improving the thickness of gland-lubricating layer was discussed.The high temperature gland-lubricating layer is prepared by vacuum-pressure electromagnetic induction melting infiltration process, based on the design of composite lubricants alloy. The microstructures and the lubricants distribution were analyzed by the methods of SEM and XRD. A new three dimensional model of the effective thermal conductivity prediction of high temperature gland self-lubricating composite is developed by APDL based on the microstructures characteristics of the composite, and the effective thermal conductivity of the lubricating layer is studied.The high temperature sweating and self-lubricating tribological experiments were carried out and the wear surface morphology and composition were analyzed. In the high temperature frictional process, the precipitation of lubricants and the dynamic process of lubrication film’s formation-destruction-reformation were studied.The high temperature sweating and lubricating cellular automata model was established and applied to analysis the dynamic frictional process of the high temperature sweating and self-lubricating materials. The friction coefficient, surface morphology, contact stress and friction temperature field distribution were studied. The research provided the theoretic basis for the dynamic prediction of high temperature sweating and self-lubricating process.The prediction model of the cover rate of lubrication film was developed based on the study of the cover rate of lubrication film and the effects of working condition on the lubricating performance, which was characterized by friction surface roughness, weld permeability porosity, lubricating layer thickness, material thermal expansion coefficient and working temperature. The model can not only predict the over rate of lubrication film, but also be helpful to realize the lubrication control based on working condition, materials parameters and thickness of lubricating layer.